Do you think it is a bug?

Hello,
I'm using the latest stable 5.0.1
Sometimes, when running Get File Names module I have the following exception.

It looks like a programming error, does it?

Exception in thread "get_file_names - Get TX File Names" java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
at java.util.AbstractList$Itr.next(AbstractList.java:343)
at org.pentaho.di.trans.step.BaseStep.markStop(BaseStep.java:2712)
at org.pentaho.di.trans.step.RunThread.run(RunThread.java:120)
at java.lang.Thread.run(Thread.java:662)

Thank you,
Alex